A few years ago after a little research i had planned an overnighter on this little loch but a health scare scuppered my intended visit.Maybe interest someone on here willing to get the boots on.
Beinn Donachain may not be the richest hill out there but it has its fair share of alpines and all the usuals can be found up there,seemingly a particularly nice flush can be found on its northern face around 600m.
I am no geologist but from what i can see its northern shore seems to lie on alkaline rock,its waters seem to be crystal clear with one burn which is its outlet,possibly poor spawning facilities.
A nice variety of plants within the loch the most interesting of these long stemmed pondweed,a plant that does not tolerate poor water quality and is usually only found in waters with limestone,marl and basalt geology.
Interesting little loch and as usual nothing is set in stone,might be worth a visit.
I had been planning on camping/fishing the wee lochans just to the east of this one early summer. Sounds like this one could be quite like lochan a' chaisteal although it looks more exposed from the photo.
Certainly looks pretty open and would catch a blow at that height Ian,a settled period with light winds would possibly be the best option
Whatever the fishing is like, there are great views across to Beinn Cruachan and you can't beat a bit of exploratory fishing and hill walking. :D
Ian